This invention relates generally to systems and methods for addressing an electronic display. More particularly, the invention relates to designs for active matrix backplanes that use a capacitor at each pixel electrode for driving an electronic display.
In an active matrix display, to address a pixel, a voltage is delivered to a pixel by addressing the gate (or select) line for that pixel as well as applying a voltage on the data line for that pixel. The pixel is charged up to a voltage approaching the corresponding data line voltage. After addressing the pixel, the voltage decays due to leakage through the pixel as well as through the thin-film transistor attached to the pixel. Therefore, the pixel does not experience the full voltage drop across its thickness for the entire time between addressing events. In fact, the voltage across the pixel may drop quite considerably between addressing events. This is undesirable because the optical response of the electro-optical medium is slower when the time-average voltage across the pixel is smaller. Also, the optical saturation will generally be smaller when the time-averaged voltage across the pixel is reduced.